December 12, 2017 23:20

Closest to the perfect solution was this. Still there was a problem -the lower lines did not end in pairs with the upper lines. From the second lower line on, those should end in pairs. In addition to that some of the lines did not end horizontally  - all lower lines should end horizontally. Also in addition to that lower line endings should not touch the backbone but should remain under it.  please make such minor adjustments and you can be promoted :)